Calipers



(No Model.)

3C. P. PAY.

CALIPBRS. No. 251,200. Patented 116112111881.

UNITED STATES PATENT OFFICE.

CHARLES P. FAY, OF CHICOPEE FALLS, MASSACHUSETTS.

CALIPERS.

SPECIFICATION forming part of Letters Patent No. 251,200, dated December 20, 1881.

Application filed September 29. 1881. (No model.)

To all whom it may concern Beit known that I, CHARLES P. FAY, a citizen of the United States, residing at Chicopee- Falls, in the county of Hampden and State of Massachusetts, have invented new and useful Improvements in Calipers, otl which the following is a specification.

i This invention relates to the details of the construction of hinged or pivoted leg calipers, together with devices for operating and setting them, the object being to provide calipers having screw-adjusting appliances, which can easily be held, adjusted, and manipulated while held in one hand only, and which can be constructed at a moderate cost.

In the drawings forming partot' this specicat-ion, Figure 1 is a side elevation of a pair of calipers constructed according` to myinvention. Fig. 2 is a view of the yoke, showing the position in section of the legs of the calipers therein. Y Fig. 3 is a side elevation of the spring, and Fig. 4 is a plan view ofthe same.

In the drawings, a is the head. d is the screw. c c are the legs. e is the yoke, and z' is the spring.

The legs c c of the within-described calipers are ofthe usual form, and are pivoted to the head c, which has slots in its sides to receive the ends ot said legs, by the screws o o, which pass from side to side of thehead andithrough suitable pert'orations in the ends of said legs, leaving the latter free to swing in the head.

Said head a is perforated centrally between its slotted sides, to receive therethrough the end of the screw d above its threaded portion, said end being turned a little smaller than said threaded part, and having the button x secured thereto. Thus said screw d is free to revolve in head a, but cannot move eudwise therein.

A yoke, e, is made with slotted ends to receive the legs c c, said slots being deep enough to permit of placing a spring back ot" each leg, as hereinafter set forth, and screws or pins 'v pass through each end of said yoke tra-nsversely to properly hold said legs in the yoke,

and the latter is perforated and' tapped centrally on a line with the faces of said slots to receive through it the screw d. An upwardlyprojecting collar, n, is left on the upper side of yoke e, upon which is fitted a doublearmed spring, i, said arms reaching downward into said slots in the yoke, back of the legs c, and forcing the latter apart and against the pins o o through the ends ot' the yoke. Thus turning screw d one way forces yoke e downward and draws the free ends of the legs 'toward each other, and turning said screw the other way produces the opposite eEect. The operation of said screw is very easy and free, and it can easily be turned with the fingers while held in one hand when the other hand may be holding work. Also, the within-described construction provides greater surety against any change in the adjustment ofthe calipers while being used than is enjoyed in the use of the ordinary spring-calipers having the transverse adjusting-screw.

l am aware that it is not new to insert a screw through the apex of a pair of springcalipers and connect said screw with a yoke inserted between the legs of said calipers for the purpose of opening the latter, and I do not claim such construction; but

What I claim as my invention is The within-described im proved calipers, consisting of the head a, the separate legscc,piv oted to said head, the screw d, supported therein, the yoke e, each end of which incloses one ot' said legs and is tapped centrally to receive said screw, and the spring t', secured to the upper side of yoke e, and having two arms, the ends of which bear against the inner sides ot' legs c, all combined and operating substantially as set forth.

CHARLES P. FAY.

Witnesses:

-WM. F. FAY,

H. A. OHAPIN. 

